Issued by NWS Denver/Boulder, CO
000 FXUS65 KBOU 052010 AFDBOU AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 210 PM MDT TUE MAY 5 2009 .SHORT TERM...WARM AIR ALOFT...AROUND 450 MB...CONTINUES TO RESTRAIN CONVECTION THIS AFTERNOON. MOST OF THE CLOUDS ARE REMAINING SHALLOW...THOUGH THERE IS POTENTIAL FOR SOME UPDRAFTS TO WEAKLY PENETRATE THIS LEVEL. WESTERLY FLOW ALOFT MIXING DRIER AIR TO THE SURFACE AS WELL...AND WEAK SHORTWAVE CROSSING THE AREA WITH SUBSIDENCE BEHIND THIS. WITH THE DRYING AND SUBSIDENCE AND A MARGINAL SITUATION ANYWAY...I WILL END THE CHANCE OF RAIN IN DENVER AT 00Z AND IN THE MOUNTAINS AND EASTERN BORDER BY MID EVENING. STILL A FAIR AMOUNT OF MID LEVEL MOISTURE UPSTREAM FOR OVERNIGHT THOUGH SUBSIDENCE MAY ERODE THIS WITH TIME. ON WEDNESDAY THE AIRMASS WARMS A LITTLE THROUGHOUT...BUT WITH LIMITED MOISTURE IT LOOKS LIKE ONLY SHALLOW CONVECTION...PROBABLY LESS THAN TODAY. CURRENT FORECAST LOOKS PRETTY GOOD...INCREASED THE DIURNAL RANGE IN THE MOUNTAINS A LITTLE...STILL CLOSE TO THE NAM GUIDANCE AND A LITTLE COOLER THAN THE GFS. .LONG TERM...NOT MUCH TO CHANGE THROUGH THE PERIOD. THE MDLS CONTINUE TO INDICATE A STG ZONAL FLOW OVER COLORADO THROUGH MUCH OF THE PERIOD...WITH WEAK EMBEDDED SYSTEMS PASSING TO THE NORTH OF THE STATE. THE MDLS INDICATE THE LEADING EDGE OF A 120KT UPPER JET MOVING INTO NRN COLORADO WEDNESDAY EVENING...MAYBE ENUF MSTR FOR A FEW STORMS IN THE NERN CORNER SO WL LEAVE THAT AS IS. A WEAK FRONTAL BNDRY IS PROGGED TO SLIP INTO THE NERN PLAINS ON THURSDAY. INTERACTIVE SOUNDINGS NOT ALL THAT IMPRESSIVE WITH THE CAPE ON THURSDAY (200-600 J/KG) BUT ENUF TO HANG ON TO SLGT CHC TSTMS IN THE GRIDS. THERE COULD BE ENUF OF A PUSH WITH THE BOUNDARY TO INITIATE A FEW SHOWERS OR TSTMS LATE IN THE DAY. STORMS SHOULD BE HIGH BASED WITH MAINLY GUSTY WINDS AND SOME LGT RAINFALL. AN UPPER LEVEL TROF IS THEN PROGGED TO PASS INTO THE NRN GREAT PLAINS LATE THURSDAY NIGHT INTO FRIDAY MORNING...WITH A MORE PRONOUNCED COLD FRONT SLIPPING INTO THE CWFA LATE FRIDAY AFTN AND FRIDAY NIGHT. AMS SHOULD BE FAIRLY CAPPED ON FRIDAY SO WL CONFINE THE TSTM POTENTIAL THE FOOTHILLS. THE ZONAL FLOW IS PROGGED TO CONTINUE INTO THE WEEKEND...WITH SOME LOW LEVEL MSTR GRADUALLY INCREASING FROM THE SOUTHEAST. THE GFS INDICATED ENUF MSTR AND INSTBY TO WARRANT A SLIGHT CHANCE DURING THE AFTN/EVENING FOR BOTH SATURDAY AND SUNDAY...WITH THE BEST POTENTIAL ON SUNDAY. THERE MAY BE TOO MUCH OF A CAP ON SATURDAY...BUT SOME POTENTIAL DURING THE LATE AFTN AND EVENING. THE GFS THEN MOVES ANOTHER TROF ACROSS WYOMING LATE SUNDAY NIGHT INTO MONDAY...A DRIER AND MORE SUBSIDENT CONDITIONS PROGGED FOR MONDAY WITH MORE RDGG ALOFT. TUESDAY LOOKS DRY AND WELL WITH AN INCREASING SWLY FLOW DVLPG OVER THE STATE AHD OF ANOTHER PSBL SYSTEM MOVING INTO NEVADA. && .AVIATION...VFR CONDITIONS ARE EXPECTED THROUGH WEDNESDAY. ONLY ISOLATED LIGHT SHOWERS THROUGH THIS AFTERNOON. SOUTHERLY DRAINAGE WINDS SHOULD DEVELOP AT DEN BY MID EVENING. WINDS WILL GO WEST TO NORTHWEST AGAIN WEDNESDAY AFTERNOON BUT SHOULD BE LESS GUSTY THAN TODAY. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. $$ CMG/FMC
